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AssigneeMurata Manufacturing Co., Ltd.
InventorHIRONORI SAKAI
Estimating the term…
The frequency of an AC voltage applied to an active electrode and a passive electrode of a power transmission device is swept and input impedance (input voltage DCV) of a power receiving device side as viewed from a DC-to-AC inverter circuit is detected for each change of the frequency of the AC voltage. A determination is made as to whether the input voltage DCV in a first frequency range determined by a resonant frequency of a series resonance circuit of the power transmission device and parallel resonance circuit of the power receiving device falls with a range of 25 mV to 450 mV, and the input voltage DCV detected in a second frequency range is equal to or lower than 100 mv. When the results of both determinations are true, power is transmitted to the power receiving device.
A power transmission device for wirelessly transmitting electric power to an external device of the type which includes a first resonance circuit and first power coupling means coupled to the first resonance circuit, the power transmission device comprising:
A wireless power transmission system comprising:
A method for determining when to transmit power from a power transmission device to a power receiving device, the power receiving device having a first resonance circuit and first power coupling means coupled to the first resonance circuit, the power transmission device having a second power coupling means for transmitting power to the power receiving device via the first power coupling means and an alternating current generation circuit that applies an AC voltage to the second power coupling means through the resonance circuit for transmission of power to the external device;
Dependencies are inferred from the claim text.